function inheritPrototype(SubType, SuperType) {
  SubType.prototype = Object.create(SuperType.prototype)
  Object.defineProperty(SubType.prototype, "constructor", {
    enumerable: true,
    configurable: true,
    writable: true,
    value: SubType
  })
}

function Person() {


}

function Student() {

}
inheritPrototype(Student, Person)

var stu = new Student()
// 是否出现在原型链里面
console.log(stu instanceof Student);
console.log(stu instanceof Person);
console.log(stu instanceof Object);

